Hydrodynamic torque converter



Sept. 11, 1956 F. E. ULLERY HYDRODYNAMIC TORQUE CONVERTER 5 Sheds-Sheet2 Filed Nov. 7, 1951 w 7 Oul'puf Shaff Speed-rpm H000 INVENTOR.

0 2- 2 6 OufpufSha/f s eed-n 'mr-laoo Sept. 11, 1956 F. E. ULLERY2,762,196

HYDRODYNAMIC TORQUE CONVERTER Filed Nov. 7, 1951 ,fifl 22. NOMENCLATUREn at entrance sn atsfatar entrance x of exit 5x af stator exit f'sx -atfinal stator exit I turbine pt -preceding furbine ptx at the precedingturbine exit ftn *at the following turbine entrance 5 Sheets-Sheet 5F29. 23. EQUATIONS OFA FREE-WH/RLING MEMBER 771e moment ofmarnentum atthe exit of the member is equal to that of the fluid prior to entrance,

h 62 Rn w ence ZITNRx 4- [Tx fanBx Vcr (a) which is the free mrtex lawthat the circumferential Velocity Varies inverse/g as the radius.

from ea. /al l is Q N- 217 Rx fi Rx 34x fan/8x] (6} hence, the fluidc/rcurnferential Velocity just after entrance is Rn Rn Q Q FTXVC/'Efanfix)+f;/dnfln (C) The change from. Vcr to ea. (cl is the shockvelocity, and

Wen-e e and the approximate Shock head loss atentrance in ft,

3 29. 24. FREEWH/RL/NG' 5T4 TOR HAVING BLADE ENTRANCE SWYCHRO/I/ZED w/rnTHE FL um In eg. fdl, substitute flwr l tr the circumferential velocityof the fluid as discharged by the preceding turbine member and radial/ymodified, provide ap ropriate suffixes, and equate to 0,

hence Rptk 9 phase approximate/g when the power source is developing itsrated power, the corresponding turbine speed be 'ng Nr, and theparticular rate of circulation being Q. Also,

provide practical limits 0.3 Q /Asn. Then the spec/tic relationship is,

Rm! 1 i /77 5 1 2' Rs 277 Hr Rptx 4 ix fan bptx l RSX As tan Esn fisxAsx fanfisx O-QJ (g) e f- 2 TURBINE MEMBER HAVING BLADE ENTRANCE.SYNCHRO/t/ZED W/77-l THE FLU/D Specifically, being the followingturbine of two successive turblne memberswhich are united rotational/yand have an intervening free-whirling stator member.

Radial/g modify the circumferential Velocity of the fluid dischargedfrom the preceding turbine member and equate to the fluidcircumferential velocity just after entrance in the follow/71g turbinemember; hence hence This relationship is desired in the coup/in ratedpower; the corresponding turbine speed g phase approximate/g when thepower source is developing its being Nt, and the particular rate ofcirculation being Q. Also,

provide practical limitr, I 0.3 Q /Aftn. Then the specific relationshiprls,

% 2 COUPLING POINT EQUATION Specifically, the relationship of Ntc m.-

member; and the exit features of the nearest 1 for the final statormember; torque 0, a

turbine member; R m

whence Rfsx Q p A Rial Nfc Rpfx Aptx fans, '27

the rate of circulation, the exit features of the final stator rbinemember preceding the final stator member.

nd speed: 0, at the coupling point Hence, the circum ferentia/ Velocityat the exit of the final stator member is equal to the radially modifiedcircumferential velocity at the exit of the nearest preced/ng INVEN TOR.

iced aimin i United States Patent-O HYDRODYNAMIC TORQUE CONVERTER FredE. Ullery, Detroit, Mich.

Application November 7, 1951, Serial No. 255,167

59 Claims. (Cl. 60-54) This application is a continuation-in-part of mypending application Serial No. 238,459, filed July 25, 1951, which maybe considered the parent application. There are continuation-impartapplications relating to inventions which are at least partiallydisclosed herein. Those applications are as follows: Serial No. 261,702,filed December 14, 1951; Serial No. 271,550, filed February 14, 1952;Serial No. 283,090, filed April 18, 1952; and Serial No. 286,117, filedMay 5, 1952.

Also, there are other applications claiming inventions undisclosedherein, but using a disclosed embodiment hereof as a setting. Thoseapplications are: Serial No. 298,560, filed July 12, 1952; and SerialNo. 313,471, filed October 7, 1952.

The invention of this particular application relates to an improvedclass of hydrodynamic torque converters with physical features conduciveto high torque ratio near stall, and high efliciency near to and in acoupling phase of operation. This family or class of torque convertersis not restricted to any particular field of application or usage, butis especially desirable for any application needing or requiring aneflicient coupling phase.

This improved class of torque converters includes various combinationsof bladed members, with each combination having, a multi-stage turbinearrangement and novel features characterizing particular members.Herein, a multi-stage turbine arrangement is considered that having,plural turbine members in the fluid circuit with at least oneinterrupted space between the first and the final turbine members, andat least one stator member interposed in each interrupted space.

The invention of this application and that of the parent application aredistinct inventions which may be used in co-operative relationship insome embodiments of torque converters, but neither invention isrestricted to embodiments of the other. The invention of the parentapplication relates to a novel class of torque converters with certainunique physical features, and having a unique humpbacked form of inputspeed curve; thus permitting the power source unusual freedom to developpower. The present application concerns improvements which give moreeflicient conversion of the input power to output convert the inputpower to output power as desired, but with a generally reduced rate offluid circulation,'ob-

viously lowering the circulation head losses and also some Some of theinfluences and characteristics of multistage turbine arrangements arewell known in the art. It is generally known that multi-staging improvestorque ratio near stall, and that a stator member positioned in theouter portion of the fluid circuit aids stall reaction torque more thana similar stator member positioned radially closer to the axis of thetorque converter. Also, that fixed stator members subsequently in thehigh speed ratio range have adverse influences, the most serious beingshock head loss, causing a rapid drop in efliciency; and that statormembers which characteristically, are most advantageous at stall, aremost detrlmental at high speed ratio operation. Consequently, the use ofthese arrangements have been limited generally to applications, such as:installations using the torque converter only for the startingoperation, and cutting it out of the drive train for normal operation;and situations for which the adpower. The concepts of some of theseimprovements were disclosed and partially discussed in the parentapplication. 7

Furthermore, the preferred embodiment exemplified and described for thisapplication is the same as that of the parent application. In thispreferred embodiment, both of these inventions cooperate to achieve thesuperior characteristics disclosed. 1

One important object of this invention is to reduce and practicallyeliminate in the coupling phase, the shock head loss at the entrance ofa stator member.

Another important object is to reduce and practically eliminate in thecoupling phase, the shock head loss at the entrance of a particularturbine member which follows a stator member. 7

A principal object is to provide torque converters which for both.Various forms of retractile members have been proposed, some of thesimpler versions merely withdrew the blades from the fluid circuit, butothers were shuttle type, having two or more rows of blades which couldbe successively positioned in the fluid circuit, each row of bladesbeing disposed angularly for a particular range of operation.

Another group of devices are those having pivoted blades, many types ofwhich are shown in the prior art. Some of these have the angulardisposition of blades externally controlled, some have centrifugalinfluences to vary the blade angles, and others have blades which areindividually one-way acting, each blade having a stop in one directionbut being free swinging in the other. Some devices have a single row ofpivoted blades, or a row of pivoted blades auxiliary to the entrance ofa row of fixed blades, and some show plural rows of overlapping pivotedblades having a shingled form near stall, but a staggered louvredisposition for high speed operation.

Also, there are a variety of one-way rotatory stator members shown inthe prior art: some with a separately controlled brake arrangement; andothers having various forms of one-way devices, preventing backward butpermitting forward rotation of the stator member or members. Some ofthese arrangements include clutching means to subsequently secure astator member to the preceding turbine member or to the followingturbine or pump member. Apparently to simulate clutching to a turbinemember, one device shows for a stator member, an exit radius smallerthan its entrance radius, so that when the apparatus is transmittingthe-maximum available power, thefstator member is driven or tends to bedriven forwardly by the liquid substantially at thesame speed ofrotation as the turbine.

he. .one-way rotatory. stator of these. various si vefacceptance. Mostof 'the current torque converters. bananas err-we stator members, eachpositioned in the fora mechanical drivej In each BIIlhQdlIfiBl'lt orthis invention; each tatormeniw her s app'roKimately onewayacting. Mostof'the stator. member-shave a respective one-way device to providethis'characteristic, butiwo stator members which inherennynav similarforward speedicharacteristics may be 7 joined and provided with a:single one-way device.

A "lhis invention conternplat'es, the construction having thegentranceand the'e'xitlfeatures of a one-way acting stator member correlated, andirelated to the environ ment, so that in thecouplingphase (usuallyearly), the fluid immediately after entrance to the stator blades isapproximately'synehronized with the approaching fluid; that is,;thefluid. enters the stator blades with little or no change incircumferential velocity, practically eliminating shock headfloss at theparticular entrance. Unless the entranceradius of the stator member isconsiderably smaller than the exit radius of the preceding turbinemember, this shochless situation requires a rotational speed of thestator member considerably slower than that of the preceding turbinemember.the blade angle at the angle at the exit of the preceding turbinemember, and desirably so, as explained later in this specification.

' This; invention includes the concept of having two turbine memberswith at least one intervening oneeway actin'g'istatonmember,andhavingathe exit features of the preceding turbine and the entrancefeatures of the following turbine correlated andrelated 'to theenvironment, so that in the coupling phase (usuallyearlyL-the fluidimmediately after entrance to the blades" of the" following turbinemember is approximatelysynchronized withthe approaching fluidfthat is,the fluid enters the bladee of the following turbine member with littleor hating" shock head; loss at the particular entrance; 7'The'se'imprdyernents permit theme of armulti-sta ge exitjof the-nearestpreceding turbine member"thus'furthering high efficiency near to and'inthe coupling phase.

The'outer stator member relieves the inner stator'mem Mr or members ofmuch of the reaction requirements a variety r a epeated.

member v is beauty one, typeset devices that has received exten-.

"nears; mas general and 7 ment in efficiency is 'obtained+-the lossheads bemg rei duced and being relative to the corresponding gross headwhich is increased. The rate of circulation being reduced, the pump andturbine members fora particular application obviously are granted largerradial propor- 4 tions to provide the required change of moment ofmomentum of'the circulatingfluid. Thus for alparticu lar application thediameter of the torque on'verter is increased which'obi'ionsly isfavorable for high efliciency in the coupling phase. a

In the sccempza 'mg drawings'frdrmin a part of this 7 specification? 7Za -f Figure l} showing .t he"a.rr'angementlof.the one waydevicesjpositioned in the'cor'e cavity;

Figure l is somewhat more than a half section longitudinally through theaxisof rotation of thepreferred embodiment; a Figure 2 is an enlargedfragmentary sectionon-line Figure 3' is an'en'larg'ed'fragmentarysectionfon line 3%3' of Figure .1, showing thearranger'nentof theorieway devices positioned between the'fiuid recirculating pathand the airis'of rotation;

, Figure 1;

- stator entrance being decidedly different from the blade, Figure/'7 isa diagram illustrative of h grss a a no c'ha'ng e in circumferentialvelocity, practically elimi-- turb'ine arrangement in 'a' torqueconverter combination 7 area at th e exit of the final stator member'andat the near stall, permitting the particular features favorablefor highefiiciency in the coupling phase. Furthermore, this invention includesthe concept of having a multistage arrangement in a torque converter 7combination; in which multi-staging is extensively providedfor'the'general improvement of efliciency, having I the desired reactiontorque. .This' reduction in the'rate ofzcirc'ulation, lowers thecirculation head losses and some J f'of-g the shockehead losses, andinversely raises the gross Figure 4 is a diagram illustrative ofthe'efliciency' and torque ratio characteristics or the preferredembodiment illustratedin Figure 1; i V, v V i Figured is a diagramillustrative of the rotativespeeds of the respective bladed members ofthe preferred" em bodiment illustratedin Figure l j "Figure 6 is adiagram illustrative of the rate or fluid circulation in the preferredembodiment illustrated in and the total loss head of the preferredembodiment illustratedinFi'gure 1;" e V Figures 8; 9; 10 11,12, 13, and14 are diagrams il-' lustrat'ive .of'shock head'losses at the entranceof the. I bladed members respectively, pump, first turbine, second;turbine, third turbine, first statons'ec'ond stator, and thirdstatorjofthe embodiment illustrated in Figure 1;

Figure 15 isla sketch of afstator blade and theeXit portion of'a-turbine blade, diagrammatically illustrating a: desirable dispositionof the stator entrance angle rela- 'tive: to its' exit angle and'thatofitheturbine blade;

Figu're l6is a sketch of a stator blade and the exit portion of'aturbine blade, diagrammatically illustrating. thGvdlSPOSiIiOII' ofithestator entrance anglerelative' the turbine blade exit angle requiredforfshockless entrance when the' stator rotates in .unisonance with. theturbine; E F1gure 17' is a somewhat diagrammatical illustration:

of: an embodiment with six bladedimembers, one pump, threeturbinesiaridtwo statormembers'; a

. Figure -l8:israsomewhat diagrammatical illustrationof I an embodimentwith six bladed members, one pump, two turbines, and three statormembers;

. Figure 19, is a somewhat diagrammaticahillustration V of anembodimentwith five bladed members, one pump,

two turbines, andtwostator members;

Figure 20 is a somewhat. diagrammatieal illustration I of an'embodiment,with seven bladed members as illus trated in; Figure 1; but. withrelocation of two of the oneway devices of the stator combination, andhaving the third turbine member rotationally united with'the firstturbine member;

, Figuref2l:.is' a' somewha-f turbines, and five stator members;

Figurei22 isatabnlation'of term'slusedin derivations V of various:relationships in- Figures I 23526 inch;

' velocity mdisliockheadequations; a

a Figure 24 shows thederivation of' the eqnfiorra the equationforparticularconditions; j

quite substantial improve 7 V diagrammaticalillustration of anembodimentwith ten bladed members, one-pump, four 7 Figure 23 showsithederivation'of'the equations" for a tee-whirling" member, includingrotational speed, shock Figure 25 shows the derivation of the equationfor shockless entrance to a particular turbine member and the equationfor particular conditions; and, V

Figure 26 shows the derivation of the equation revealing therelationships at the coupling point.

Terminology and basic relationships Before describing the specificdetails of this invention, it appears desirable to define some of theterms, and to establish some of the basic relationships, which influencethe unique characteristics obtained thereby rendering the specificationmore significant and expressive of intention and purpose and reducingperiodicexplanations.

Except as noted, terms used herein are as recommended and with themeaning as defined in Hydrodynamic Drive Terminology, pages 738740 ofthe 1951 S. A. E. Handbook, published by the Society of AutomotiveEngineers, Inc. Where optional terms are listed, the first is consideredpreferable and will be used in this specification.

As used in this specification, a hydrodynamic torque converter is adrive that transmits power by dynamic fluid action in a closedrecirculating path of toroidal form and has a fluid coupling phase aswell as torque conversion phases of operation, and physically comprises:a plurality of co-axial members including at least, one pump, twoturbines and two stators, with mountings to maintain axial spacedrelationship and to permit each member to rotate forwardly about thecommon axis in at least one phase of operation; a fluid system includingan adequate fluid supply and suitable fluid control, as well as acooling means if required; and structural components including, astationary housing or support structure, a rotatory casing with suitableseals, an input power structure, an output power shaft or structure, anda reaction torque structure.

Each member has at least one row of circumferentially spaced blades,extending across a fluid path between core and shell shroud elements,which respectively, define part of the core and shell boundaries of thefluid recirculating path. Obviously, if desired for some members, one ofthe shroud elements could be omitted, the blades being projected fromand supported by one shroud element, and the fluid path boundaryfunction of the omitted element provided in another manner.

Each member is externally associated in accordance with its specificcharacter, being joined by a respective attaching construction to theproper driving, driven, or reaction structure: a pump member is joinedto an input power driving structure to cause forward rotation andtotransmit power to the circulating fluid; a turbine member is joined toa driven structure communicating with an output power shaft orstructure, enabling it to contribute torque at least in the forwarddirection to the output shaft; and, a stator member is joined to areaction structure associated with the stationary housing, enabling itto transmit torque to the stationary housing at least in the backwarddirection.

The driving structure for a pump member, the driven structure for aturbine member, or the reaction structure for a stator member, may be, asimple element, a series of elements which may include one or morekindred members as structural elements, or a trunk arrangement with aparticular confluent branch; and may include a device rendering theparticular member one-way acting relative to its external association.The attaching construction of a member is the means of ataching themember to, and is part of, its particular driving, driven, or reactionstructure. It may be, a mating surface, a conjunctive element, or aseries of elements; and may include a device rendering the particularmember one-way acting.

Forward rotation is the direction of rotation of the pump member. Allvector quantities in the forward direction are considered positive, andin the backward direction,

negative.

Fluid circuit refers to the fluid recirculating path. The

average radius of the fluid circuit is the average of, the

largest design radius, and the smallest design radius'of the fluidcircuit. In reference to the fluid circuit, the outer half and the innerhalf indicate respectively, the radially outward portion and theradially inward portion, relative to the average radius of the fluidcircuit. Accordingly, an outer member has the design radii of its bladeslarger, and an inner member has the design radii of its blades smaller,than. the average radius of the fluidcircuit.

Rate of circulation is the volume of fluid per unit time passing aparticular location, and herein is expressed, cu. ft. per sec. Being aclosed path, the rate is simultaneously constant throughout the fluidcircuit.

The circulation velocity is the component of the fluid absolute velocityin a plane passing through the axis of rotation. The circulation patharea being the area'normal to the circulation velocity, the circulationvelocity is the rate of circulation divided by the circulation 'pat harea.

Physically defined, the circulation path area" tat a specified locationof the fluid circuit is the portion of the area of a particular surfaceof revolution which cuts across the fluid channels between the blades,that surface of revolution being that generatedabout the torque.converter axis of rotation by a line which, at the specified location,is perpendicular to the design path and extends from the core to theshell shroud. In other words, the circulation path area is the area ofthe particular surface of revolution less the areas'of the bladesections cut by that surface of revolution. If, at the specifiedlocation, the design path is axially disposed, the surface of revolutionis an annular plane surface; it the design path is radially dis posed,that surface is a lateral surface of a cylinder; otherwise, the surfaceof revolution is the lateral surface of the frustum of a cone.

The circumferential velocity of the fluid is the component of the fluidabsolute velocity in a plane perpendicular to the axis of rotation.

The term blade angle as used herein refers to the effective blade angle,being the included angle between the fluid absolute velocity and a planewhich passes through the axis of rotation and rotates in unison with theblades. Blade angles are considered positive and negative, 7respectively, for forward and backward circumferential components withthe normal direction of fluid circulation. a

The input power head is called the gross head/ In equation form, thegross head, ft, equals 1 Power input, ft. lbs. per-sec. Rate ofcirculation X Fluid specific weight in which, rate of circulation is cu.ft. per sec., and fluid specific weight is lbs. per cu. ft. Theinfluence of a loss head is relative to the corresponding gross head;that is,

loss head, ft.

gross head, ft. X

Loss, per cent, equals It is this particular combination of factorswhich permits a torque converter to have a high efliciency in thecoupling phase. As shown by Fig; 6, the rate of circulation in thecoupling phase is low, tending to be a low circulation head loss inspite of blade configurations, and at the same time as shovm by Fig. 7,the corresponding gross head is very high; consequently, the actual lossin per cent may be quite low in the coupling phase of a torqueconverter.

The hydraulic losses are divided into two distinct groups; namely,circulation head losses and shock head losses. The circulation head isthat required to overcome the flow resistance of the passages and thecoincidental turbulence with the particular rate of circulation.

The shock head losses are attendant to the circumferential velocity ofthe fluid. Such a loss is entailed at a blade entrance which requires asudden change in the fluid circumferential velocity. This velocitychange is 1 At any specific 1 thsl h l yelbi y" I The tte in htic ead nrfit l i" f f Constant shock velocity, ft. per sec.)

Actually, it varies withfthe blade entranceftip form, thelblade spacing,and th'eangle of impingement,

,hichjis-the angle, of misalignment of the approaching flu f rorn' the.blade disposition; Also, it is generally larger for back-impingement onthe blades, than it is for faceimpingement .Herein, the shock head forface inrpingeinent; .is' (galls-{1 face shock head, and for backimpingement, backfshock, head.

The .curvesIofaEigs. 4,-1.4 incl are based onan input qu ssim atinsconditions may be constructed by applying the basic torque con er er r lonsh p r 1 Pump torqi'leplus'stator torque equals turbine torque, Speedratio fX torque per cent; i ,7

speed'ratio: V i

Pump torque'rand thehydraulic heads vary directly t ras'the secondpower'of thepump speed. 7 V Fluid circulation varies directly as :thepump speed,

7 V .th'eitwide. open'throttle torque of a. particularlengine.Comparable curves for partial throttle ratio' X100 equals efliciency,

WM museum in l' Phas ffl n ation f herat i ulai Flam- 2 e J a eewhir inmember m y have o her in,- r

' nance whi h are v ry detriment l; hydrauli l y, that is,

t of relationships for a free-whirling member are derived yj in Figure'23 withexplanatory notes.-

' Hence, it the pump torque is reduce'd to one-fourth of its originaltorque and the speed ratio of the output speed t o, the inpu sp d i ma sth Pu pe n that of all other members'will be reduced to one-half, all

members retaining their original speed ratios; the rate of fluidcirculation is also reduced to one-half; and, all the torques and thehydraulicfheads are reduced toonefourth of their respective originalvalues; Thus, if the particular speed ratio exemplified was'that of thecou- 'pling point, the torque conversion range would be reducedtoone-half of its original speed range.- This is presented to point outthat phase changes concur with respective speed ratios, and notaccording'to specificoub' 7 put speeds. Also to emphasize that forpart-load operation; the a speed range oftorq'ue conversion compresses,

a'ndthat of coupling-operation expands; thus showing the importance ofhigh efiiciencyin the coupling phasefor many applications, most of; theusage requires only a fraction of the available torque of the powersource, hence l i n a h k he use I i appare h t 1 free-whirling'memberadds to the circulation head loss according to the flow resistance. ofits bladed passages;

however, this loss is small in the late phases of operation 7 when therate of fluid cir ulation is relatively low.

The most serious influence of a free-whirling member usually is itsrespective shock head loss, The namre oi this loss is dependent on theform of the particular momber relative to the physical environment.

0 ma e r e u e a d' b an a y l m r nated in some phases; Control of,these losses is avit ai. factor in obtaining high 'efiicie'nc'y of.powertransmission 2 with which this invention is-objectively concerned;a

With. symbols as tabulated in; Figure 22', the equations For zero'shock'vel'ocity equation, ('dlisequalto zero,

, and gives the proportions of radii and passage areas of a for 7 memberrequired to eliminate the shock head loss a particular circumferentialvelocity a t-entrance. Thephysical significance is simplelthe' absolutevelocity, of

the fluid directionally varies to conforrn generally to the bladecfiective curvature, atleast'at entrance as well as at exit, whenthe'shock velocity is equal to zero; 7

. It has been stated that a free-wh'rling mem appreciably; change themomentof momentum of the circulatingfluid; This is true concerning tbetotal efiect, I V but.norrnally, there'is an intervening fluctuation,Withf 7 1 the change in circumferential velocity (shock velocity) at theblade entrance, thcre is 'a corresponding change'inthe'moment ofmornentum which imparts an impulse drive to the blades. As thefluidpasse'sfthrough to the blade exih' there isa counterbalancing reactiondrive on the blades, restoring the moment of momentum of the circulatingfluid; j

Characteristically, the free-whirling state of a member starts after anappreciable angle of 'backimpingement has developed. Subsequently, thisimpingement may ac- 1 tually veer to the face side of the blades byvirtue of tends to be operation, near to, or in the coupling phase. 7

Y A one-way device is the term used in this specification for amechanism to render a bladed member one-way acting relative to itsrespectivecxternal association. It is suitably positioned in'theconnecting structure extending v from thejparticular member to itsrespective external association, enabling thememberto transmit torquethere.-

to but only in a specific direction, and permitting relative rotation ofthemember in the opposite direction. Figures 2 and 3 illustrate suitableone-way devices for the embodimentsof this specification.

qnsidering the moment of momentum of ing fluid vecton'ally positive inthe forward direction, and negative in the backward direction: a statormember with a one-way devicecan increase, but can not reduce the momentof momentum; and a turbine member with a one-way device can reduce, butcan not increase the moment of momentum of the circulating fluid.Actually,

fthere'is 'a slight influence counter to the direction of relativerotation due to friction in the one-way device and 'inthe"rotational'mounting of the member, some of which may be intentionallyprovided to damp rotational hunting and fluctuation of the member.

the circulat- Free-whirling is the term used herein, to distinctlyindicate the'state of free rotation of a member by'virtue oi aone vvaydevicevin the connecting structure :of the particular member. V

' As previously stated, a free-whirling member does not ap r i y h nge hmom t iii-momentum oi th circulating fluid, and hence, free-whirling isa non-func relationships shown 'inequation (d) For a fr'ee-whirling'stator member, it is desirable that the fluid enter the blades withoutshock head loss'early in'the couplingpliase. Aspreviously shown thecoupling phase expands over awide speed range 'for-part-loadoperatiomandit is accordingly important to provide high efliciency inthisphasewhicli is used extensively for most applications.

In the embodimentsof this specification, the-fluid appreaching afree-whirling stator member, is dominated by the'exit of' the nearestpreceding turbine member; So,

the circumferential velocity of the approaching fluid is that at theexit of the nearest preceding turbine member,

' modified inversely as the change of radiusfrorn the exit of theturbine blade'exit vectorially less, and-considerablyti l:- be shown so,than'that of the stator entrance; This wi with the aid or two simplediagrams. 3 V

Figures'lS and '16 show hypothetical blades. Each figure shows the'exitportion'ofa turbine blade witlrxan; exit angleofi 0; 3.I1:(l asubsequent stator member: blade haying an exit angle of ln Figur e l5,the entrance, angle of the stator blade is zero; in Figure 16, thatangle is 0,

Fo t n t y with due' consideration of the pertinent factors, the shockher-does not;

9 the same as that of the turbine blade exit, being the rela tionshiprequired for zero shock velocity when the particular stator and turbinemembers rotate in unisonance. It will be shown that the latterdisposition involves a serious shock head loss in the region where thestator starts free-whirling.

To further simplify the exemplification, without taking undue liberty,it may be assumed that both, the circulation path area and the designradius, are the same for both illustrations, and are constant from theturbine exit to the stator exit. Hence, the circulation velocity issimultaneously constant from the turbine exit to the stator exit, beingthe instantaneous rate of circulation divided by the circulation patharea, and is represented by V}. Consequently, the circumferentialcomponent at the turbine blade exit is V; tan ()=V; tan 0; that at thestator blade exit is V; tan with the total change being V1 (tan 0 tan4;). To give tangible significance, it is assumed that tan 0 tan qtequals 1.50, which is a conservative figurein some well known torqueconverters, the comparable value is close to or even in excess of 3.00.To give further tangible significance, the various shock head losseswill be expressed as percentages of the kinetic energy head of thecirculation velocity, and which is (V;) /2g.

In Figure 15, evenly divide the total circumferential change, so thatthe extent of change at entrance is the same as the subsequent changethrough the stator, tan 0 being 0.75 and tan being 0.75. Then at stallthe fluid impinges on the face of the stator blade with a shock velocityof 0.75V and the shock head is 56%% of (V /2g. As the turbine speedincreases from stall, this impingement veers to the back side of theblade, and the stator free-whirls when the angle of impingementcoincides with angle the shock velocity being 0.75 V and the shock headloss, 56%% of (VIP/2g. With a constant circulation path area and designradius through the stator, this relationship would continue throughsubsequent phases, the actual shock head in feet dropping, of course, asV; decreases. However, with the proper radius and/ or area changesthrough the stator member, this shock velocity may be practicallyeliminated for a subsequent speed ratio of the torque converter.

Here, it is important to note the result of more extensive radius and/orarea changes to bring the stator to rotational unisonance with theturbine member. Then the fluid would impinge on the face side with ashock velocity of 0.75 V; and a shock head loss of 56%% of (Vr) /2g,which is of the same magnitude as that for the constant radius and areasituation. Furthermore, beyond this resonant condition, the shock headrises rapidly as the stator speed exceeds that of the turbine.

For the stator blade shown in Figure 16, the shock velocity at stall iszero. From stall, the angle of fluid impingement on the back of theblade increases until it is equal to angle then the stator free-whirls.At this point, the shock velocity is V1(tan tan 0) and equals 1.50Vf,and the shock head loss is 225% of VI /2g. With the constant radius andarea assumed, this relationship would continue for subsequent phases,the shock head loss in feet dropping with the decreasing V1; but with asuitable radius and/or area changes, the rotation of the stator membercould be made unisonant with the turbine member at a later speed ratioof the torque converter.

This loss near and at the point of free-whirling is obviouslyprohibitiveit is four times greater than that of the example of Figure15. This loss reduces, not only efficiency, but also the torque ratio.It occurs in the torque conversion range, at any point of which thetorque converter may occasionally be required to operate for aconsiderable period of time.

These cases demonstrate the importance of having the stator bladeentrance angle distinctly different from the blade exit angle of thenearest preceding turbine member. Unless there is a considerable changeof radius from the turbine exit to the stator entrance, it follows that,for Zero shock velocity at the entrance of a free-whirling stator memberin the coupling phase, the rotational speed of the stator member must besufliciently different to olfset the difference of blade components.

It is not always desirable to evenly divide the circumferential changeeffected by a stator member, as was exemplified for Figure 15.Generally, the division should be limited to within the middle third, sothat the junction change is not less than one-third or more thantwo-thirds of the total change. Otherwise, it becomes a case ofdiminishing returns in one phase at the expense of pyramiding losses inanother phase, as exemplified by Figure 16.

Using the general relationships of a free-whirling member as derived inFigure 23, the equation for a free-whirling stator member, having thefluid synchronized for shockless entrance early in the coupling phase,is derived in Figure 24; and equation (g) of Figure 24 is a practicalexpression of the particular relationships.

In multi-staging, it is also important about the same time, topractically eliminate shock head loss at the entrance of a turbinemember which follows a free-whirling stator member. The requiredrelationships of the exit features of a preceding turbine member and theentrance features of a following turbine member to each other and to theenvironment are shown in equation (j) of Figure 25.

The respective notes of equations (g) and (j) refer to basic principleswhich have been heretofore disclosed, and generally explain theparticular derivations. However, it appears desirable to further explaincertain items: the shock velocity tolerances, the turbine speed bit, atwhich the power source is developing its rated power, and the rate ofcirculation Q.

It is, of course, impractical to specify Zero shock velocity-certaintolerances must be permitted. In equations (g) and (j), the shockvelocity is specified as zero, plus or minus 0.30 of the circulationvelocity at the respective entrance, which is a close toleranceconsidering that the circulation velocity is relatively low in thecoupling phase. This permits an angle of impingement to the blade,ranging from 17 degrees on the face side to 17 degrees on the back side,if the respective blade angle is zero; but, the angle of impingementpermitted is considerably less for large entrance angles, being thedifferences of large tangent values; e. g., if the blade angle is 45degrees, the tolerances shown would permit an angle of impingementranging from about 10 degrees at one side to only 7 /2 degrees at theopposite side of the particular blade. Furthermore, these limitsrestrict the particular shock head loss to not more than 9% of thekinetic energy head of the respective circulation velocity, which is asmall figure inasmuch as the rate of circulation is low in the couplingphase. In the light of the discussions relative to Figures 15 and 16,and the complexities involved, these tolerances are relatively narrow;certainly narrow enough to indicate intent, but it is believed wideenough to permit manufacture consistently within the limits.

Nt' of equations (g) and (j) is a particular turbine speed forfull-throttle power input in the coupling phase, being the speed atwhich it is most advantageous to eliminate the particular shock headlosses. That is, bit is not less than the coupling point turbine speedfor full-throttle power input, and generally, it should be at least 10per cent greater. In the derivations, Ni is conveniently defined as aturbine speed in the coupling phase approximately when the power sourceis developing its rated power. For an automotive engine, rated powermeans maximum power; for a heavy duty engine, rated power indicates themaximum power available near the governed or at the recommended speed ofoperation. is, for wide-open throttle input'power o eration, a tu binerotational speed to per cent faster than that at the a coupling point.

1 angle is negative, the result being the sum).

7 t 7 I a "2,7623% r 11 V r t tion. It is .ge neral pra ctieeto blend atorqueconverter with an engine so that the engine speed at the couplingpoint is '5 to 20 per cent less than that at rated power. Consequently,rated power is developed in the coupling phase approximately atthe sameturbine speed at which it is desirable to have the shock losseseliminated. So, it is convenient, to define Nt 'a's'that obtained forrated input power conditions, Nt' being equal to the particular pumpspeed time's efficiency/100.

However, for the sake of "definit'enessit is preferable to dfine jNt'relative to the turbine speed at the coupling Thus,'specifi'ca'llystated with 'physic'all'i'mits, 'Nt

.Q' is'the rate of circulation concurrent with thesparticul'ar turbinespeed Nt'. V i the design rate of circulation curve, otherwise requiredto properly'proporti'on and correlate the features of the various bladedmembers;

Equation (k) of Figure point being the speed range of torque conversion.The notes preceding this equation explain. the derivation.

7 26 "showsthe requirements at the coupling point, the turbine speed atthe coupling a stator member in the ente hal 'f Thus; the high reactiontorque desirednear stall is developed with a much lower rate ofcirculation than would be required. without the outerTstat'or. Thisreduced rate of circulation reducesthe circulation head loss, offsettingthe restricting influence of the reduced areaof the inner point forWide-open throttle input power opera- 7 The value of Q is taken from Thedesired turbine speed at the: coupling point is de- "pendent on thecharacteristics of-the power source, which in 'the'torque conversionrange should be allowed to have sufiicient speed to developapproximately its maximum power. At the coupling point, the turbinespeedis equal to the pump speed times efliciency/.l"00 If. this turbinespeed is too low, the speed and the power output of the power source isaccordingly restricted,

As shown in equation (k), the co'upling point turbine 7 speed isdirectly proportional tothe rate of circulation, which as previouslyexplained should be low, to reduce the circulation head losses, and toprovide a high gross V jhead to which all head losses are relative.

The coupling point turbine speed is approximately proportional to thesumof the tangents of the blade angles at the exit of the final statormember and at'the [exit of the nearest preceding turbine member (theequation shows the 'difl'erence of these angles but the turbine Theseangles generally are made as large as practical, the limitations being:the passage choking influence of large angles, and the resulting high.flowvelocities relative to] the blade surfaces; high shock angles offluid entry into the inner stator member or members; and objectionable'warp andcontortion of the blades. 7 Also, this coupling point speed isinverselyproportional to the design radius at the exit of the nearestturbine member preceding the final stator. This radius is made as low aspractical with considerationof: the space'rethe improvement is, most-rapid for the firstjincrements.

of reduction, and decreases to insignificant gains when the totalreduction of area is about 30 per cent;

ermit 'exten The improvements of this specification p sivemulti-staging, that is, the usejof'more than one st ator member in,;orneair, the outer half of the fluid circuit. Thus, high torque ratios maybe obtained near stall with rather low rates of circulation .Hithertq:high shock losses incurred at the additional 'cntrancesjiu late phasesof operation caused low .efliciency in those late phases. :By providingthe stator and turbine members with' features in accordance with'equationslg) and (j)' respectively, those losses may be greatlyreduced, per- 7 V mitting' high 'etficiency. near to and in the couplingphase. Furthermore, by using reduced areasat the exits I.

of the final stator and the nearest preceding turbine, the gross headm'a'y be increased, also promoting high 'cfliciency. :A generalreductionof the rateof circulation grants the pump and turbine memberslarger radial pro portions 'which are conducive to'high efiiciency inthe coupling pha'se. One arrangement of extensive multistaging isillustrated in Fig-u re'2l,.which will be ex plained later in thisspecification. r

Description: A The embodiment illustratediu-Fi gure 1, is considered thepreferred-it gives physical exemplification to basic 7 concepts of thisinvention, and with diagrams of Figures 4-14 incl., shows achievement ofmany oftheipertinent objectives-of -this-invention. Also, a thoroughdescriptioniand explanation of this embodiment serves to' make.

' the features and characteristics of the simpler embodi-' mentsapparent with only brief specific comments.

. This'e'mbodiment i's an automotive application in which 7 it isintended that-the torque converter should be jsupple mented with asimple mechanical transmission at, the output shaft-end. Thistransmission should have 'areverse gear and a low ratio forward gear;"the latter, for

' unusual conditions, such as,fpr'olonged and steep-uphill quirementsfor the attaching constructions," and for the reaction and the drivenstructures; and the radius changes through 'the subsequentstator memberor members, in accordance with equation (g). f

The principal factor undiscussed in equation (k) is the'circulation patharea at the exits of the final stator member and the nearest precedingturbine member. These areas have an inverse influence on the couplingpoint turbine speed. It is customary to makethe circula- 7 .tion patharea approximately constant through the'fluid circuit. 'For theembodiments of this specification, the

circulation path area of the. inner portion of the fluid 'circuit may bemade less than that'of the outer portion.

For a particular coupling point speed, this area reduction reduces therate of circulation required, and consequently, furthers efliciency atthe coupling .pointfand in the coupling phase.

In the embodiments "of 'this'specificatiomthis reduced circulation patharea in the inner portion of the fiuid circuit is permitted by theparticular multilstaging having driving, or sustained downhill operationreqhiringabnormal engine braking. The hydraulic system of this transmission serves'thetorque converter-with an adequate supply of fluid, andprovides "the charging and the replenishing means and controls.

Referring to Figure l, a stationary housing 10 'bolted' to the rear endof the engine, encloses the torque couverter, and has a rear "face 11which in this illustration serves as an attachment surface for thesupplementary transmission, as we'llfasffor the flanged reaction shaft12 bolted thereto. This is mechanically equivalent to the generallydesirable and customary arrangement, in which the reaction 's'haft'issecured to a stationary portionof the supplementary transmission, andwhich in effect serves as part of thereac'tion structure; a

The torqueconverter cover 40 encloses the torque fconverterfluidchamberand serves as part of the pump 'driv-. ing'str'uc'ture from tlfe cnginenThis cover 'bas'aseries of. circumferentially spaced kno bs'41. Screwsthrough thewebiof the engine fly-wheel and threaded into these- 7 knobs,provide the torque converter driving connection.

An output shaft 30 transmits the torque converter put power to thesupplementary transmission.

The bladed members, in the order of arrangement of their blades in thefluid recirculating path in the direction 'of fluid circulation, andstarting at the pump entrance, are: the pump member 50, the firstturbine member 60,'the first stator member 80, the second turbine member68, the second stator member 86, the third stator member 92, and thethird turbine member 74.

The pump member 50 has a series of blades 51 across a fluid path boundedby shell 52 and core 53. The attaching construction for the pump memberincludes a skirt-like element 54 near the pump exit extending from thepump shell to the torque converter cover 40 to which it is fastened withscrews. Near the pump entrance, and extending inwardly from the pumpshell, is a hub element 55 to which is secured a sleeve 56 which isjournaled at 13 in stationary housing 10. The pump shell 52, the drivingelement 54, and the hub element 55, form part of the torque converterfluid casingfor this particular embodiment.

The turbine members are described in the order of their physicalconnection to the output shaftthe members being arranged structurally inseries relationship from a single connection to the output shaft.

The second turbine member 68 has a series of blades 69 across the fluidpath bounded by shell 70 and core 71. Near the exit of the secondturbine member and extending inwardly from the shell, is a driven hubstructure consisting of, a hub 31 splined to the output shaft 30 andriveted to a flange element 72 associated with shell 79. This element 72also serves as a rotational mounting on race 42. Near the entrance ofthe second turbine member, projecting outwardly, is a rim element 73.

The first turbine member 69 has a series of blades 61 across the fluidpath bounded by shell 62 and core 63. A driven skirt-like element 64extends from the shell, and mates with rim element 73 of the secondturbine member. At the mating junction, a driving connection is providedwhich consists of, square-head pins 65 pressed in drilled holes inelement 64, and registering with milled notches in rim element 73. Thefirst turbine core has a driving element 66, illustrated in Figure 2 asa truss-like structure integra1 with the core 63.

The third turbine member 74 has a series of blades 75 across the fluidpath bounded by shell 76 and core 77. A portion of the shell is formedto retain a bearing bushing 78, which is journaled by rim 57 protrudingfrom the pump member hub element 55; thus insuring rotationalconcentricity of the third turbine member. A one-way device 20(described in the following paragraph) is interposed between the thirdturbine core 77 and the driving element 66 associated with the firstturbine core. This one-way device prevents forward rotation, but permitsbackward rotation of the third turbine member relative to the firstturbine member, and enables the third turbine member to contributetorque through'its driven structure to the torque converter outputshaft, but only in the forward direction. As has been described, thedriven structure for the third turbine member is a series of structuralelements, including the structures of the first and second turbinemembers.

Figure 2 illustrates one suitable arrangement and construction forone-way device 20. For this particular situation, the race 32 is thedriving element of the device. This race is serrated on its innersurface and is shrunk on the third turbine core 77. The driven elementconsisting of: two annular discs 34, between which a plurality of cams33 are secured in a radially outward position relative to the race bypins 35. The annular discs in turn are secured by rivets 36 to thedriving element 66 associated with the first turbine core. The wedgingrollers 37 are urged and guided in wedging position between the cams andthe race, by arms 39 actuated by springs 38.

out

The stator members'are somewhat inseries structural ly, and will bedescribed in order of respective physical proximity to the hollowreaction shaft element 12.

The third stator member 92 has a row of blades 93 across the fluid pathbounded by shell 94 and core 95. Associated with the shell, is anelement 96 which serves as an attachment flange for a one-way device 22interposed between the third stator member and the reaction shaft 12.This construction prevents backward ,rotation, but permits forwardrotation of the third stator member relative to the reaction shaft, andenables the third stator member to transmit torque through the reactionstructure to the stationary'housing 10, but only in the backwarddirection. 1

Figure 3 illustrates one suitable arrangement and construction forone-way device 22. An inner race 14, concentric with the axis ofrotation, is spline connected to reaction shaft 12. A cam element 15,which is a thick wall race with a plurality of cam surfaces internally,is fastened by rivets 18 to shell flange 96. -Wedging rollers 16 areurged in wedging position, between the inner race and the cam surfaces,by springs 17.

The second stator member 86 has a series of blades 87 across the fluidpath bounded by shell 88 and core 89. interposed between the secondstator member and the reaction shaft 12, are one-way devices 23 and 24,the cam elements of which are attached with rivets 19 to flange element90 associated with the second stator shell. The arrangement andconstruction of each of these one-way devices is the same as thatillustrated in Figure 3 for one-way device 22. Two are used to provideadequate capacity and for interchangeability of partsobviously a singleoneway device with adequate capacity may be used. As described, theconstruction prevents backward rotation, but permits forward rotation ofthe second stator member relative to the reaction shaft, and enables thesecond stator member to transmit torque through the reaction structureto the stationary housing 10, but only in the backward direction.

The first stator member 80 has a series of blades 81 across the fluidpath bounded by shell 82 and core83. An element 84 associated with thecore provides a connection for the one-Way device 21 extending from thefirst stator core 83 to the second stator core 89. The arrangement andsonstruction of this one-way device is the same as that for one-waydevice 20 illustrated in Figure 2. The arrangement prevents backwardrotation, but permits forward rotation of the first stator memberrelative to the second stator member, and enables the first statormember to transmit torque, through the reaction structure, including thesecond stator member as a structural element, to the stationary housing10, but only in the backward direction.

Also, shown in Figure 1 is a one-way device 25 interposed between theoutput shaft 30 and the torque converter cover 40. The construction andarrangement is the same as illustrated for one-way device 22 in Figure3. This one-way device may be termed an anti-coast device. It is used toprevent forward overrun of the output shaft relative to the engine-itprovides more engine braking for downhill coasting, and aidspush-starting of the engine. This anti-coast device is not pertinent tothe invention of this specification-its inclusion is optional andgenerally complementary. These comments are included to complete thedescription of this illustration. In Figures 17 to 21 incl., thisanticoast device is omitted.

The bladed members illustrated are formed by casting; however, they maybe cast, fabricated, or otherwise made, of any suitable materialswithout departing from the intent of this specification.

Some of the specific requirements dominating blade angles will bedisclosed in a subsequent discussion. Intrinsically, turbine memberblades are curved to vectorially reduce, and stator member blades arecounter curved to vectorially increase, the moment of momentum of speedrange. of. torque conversion. 7 q it h h over a ar e pq ti n of h to ueq sr i n thejcircillating fluid. However, this;specificatiortisinotlimited to any particuiar blade formQ-blade tip form,

lade ac srfqr'. es a il v a shale-1 o kl de ji 7 any member.

Qrzmt on V V The basic principle of operation'is typical of hydrodynamictorque converters. Mechanical energy is simul: taneously transmitted to,and extracted from a flu d circulating in a closed path in which: pumpblades transmit energy to the fluid; turbine blades extract energy fromthe fluid; and intervening stator blades react and transform thephysical properties of the fluid. The objective being increasedflexibility of the torque and speed properties of the available power,in accordance with the needs'of the particular applicati0n in thisinstance an automotive drive.

range a d th c cu h cwp g Phase o pe atic? i u 5 isc s the o 's eed 9 heva ou members. This is particularly indicative of the mode of [operationin showing the respective status of each member. It rnay be noted thatthe differential speeds between the first and third turbine members, andbetween the first and second stator members are not extremely high-accordingly, the sliding velocities between the elements of theone-wayvdevices' in those respective locations are not excessive, inspite of acting at a relativelylarge radius.

A150; it should be noted thaLthe speeds of the first and.

second stator members are considerably slower than that of the first andsecond turbine, members, even in the o p n Phase 7 1 r I r r V The rateof fluid circulation of Figure v6 has the typical trend for a torqueconverter with torque conversion and coupling phases of operation. Toenable the'imembers to develop high torques at stall, the rate tends to.be relatively high; to attain high 'efliciency' in the vicinity of theW coupling'point, the rate must be' low as previously men- I tioned.However, the'rate .of circulation .of this embodi- 'ment from stall tothe coupling point is, in general, .con-.

siderably lower than that of current torque converters of comparablecapacity.

The gross 'head curve of Flgure 7 was previously explained. The grosshead is the denominator to whichthe simultaneous loss'heads are relativein the determination of efliciency.

1 in the subsequent coupling phase.

first turbine member. Thus, in this phase, the operation 7 isfunctionally that of a two-stage torque converter. .The first statormember is constructed in accordancegwith equationlg) of Figure- 24; andas indicated-in Figure 12, the shock head loss is reduced and becomesinsignificant V Comparable consid eration was given to the shock'headloss at the entrance to the second turbine blades, as'illustrated inFigure 10; Aiter the first stator member free-whirlsfthe:circumferentialvelocity of the fluid entering the second turbine memberis" dominated by the exit of the"first,turbine "member. The pertinentfeatures of these members are arranged in ac'cordancewith equation (1')of Figure 25; 7 thus, the shock headloss at the second turbine entrance15' is reduced, so that, it also'becomes insignificant in the couplingphase. l i

a The 3rd phase of'operationstarts when the third tiirbine memberfree-whirl s. In this phase, andalso in the 7 4th phase, the operationis that of a single-stage torque converter. V a 7 Throughout the torqueconversion range which includes 1st to 4th phases inclusiveythe fluid isdischarged'to the third turbine member by'the third stator member, theblades of which have a strong positive exit angle. Hence,.

the fluid has a forward circumferential velocity which is very high atstall and decreases to a low value at the l coupling point, beingproportional to the rate of circular tion. is considerably greater,being proportionalv to the second power of the rate of circulation;

The blades of the thirdturbine. member are-curved to reduce the fluidcircumferential velocity, having ana'p preciable entrance angle ofpositive character, and for Figures 8 to '14 inclusive illustrate theshock head losses Most of the shock head losses are characteristicallyhigh."

That of the first turbine member, Figure 9, tends to beself-compensating for all phases of operation-the circumierentialvelocity components ofthe adjoining blades vary in accordance with therate of circulation, and tend to offset the physical velocitydifferential 'of'the adjacent members. As shown-in the Coupling. phase;there is a slight back shock head at the first turbine blade entrance.When justified, a one waydevice couldbe interposed 'betweenthe'first andsecond turbine members. 'glnf this I particular embodiment, it'wouldonljyfunction fora high speedand'low torque situation. 7 7 V r V The2ndphase ofoperation sta'rtswhexi the first stator member startsfree-whirling in ,response ,to the increasing circumferential velecitybfthe fluiddischargedjfrom .the

' specticn of the, general shock vener a tton, equ ion this particulardesign, an 'eXit angle which is approxi-Y mately zero. In the 1st and2nd phases, 'the' blades reduce the moment of momentum, the change beingtransmitted to the output shaft as torque. V influence declines; theblade circumferential velocity in-. creases proportionally to theincreasing rotative speed of. the output shaft; and as previouslymentionedflh. circumferential velocity of .the fluid from the1hird'stat0r exit simultaneously declines? When the moment bf momentumof the fluid leaving the third Lturb'in member is equal to that of thefluid dischargedtrom' the third statoriexit, the third turbinememberfree-whirls, and rotationally lags'behind lthe outpwitsh'a'ft)=In'fact,-as

illustrated in Figure 5, its speed in the 3rd an dj4th pha'ses.

declines in conformity with the declining circumferential velocity ofthe fluid from the third stator exit; however,

in the coupling phase its speed again increases in -response to theincreasing'circumferentialvelocity of the fluidas then dominated by thesecond turbine member. 7

The shock head loss at the entrance to the third turbine member isillustrated in Figure '11, and as shown, the back shock head loss is lowin the free-whirling phases and becomes insignificant in the couplingphase; "Being a free-whirling. turbine member with blades curved toreduce the circumferentialvelocity of thefluid, i t-is desirable to havean exit design radius larger than the en trance design radius to reduceshock velocity and the at-.

tending shock head loss. This may be shown 1 n- (d) ofFigure ZS. 1 j V aH b Figure 8 illustratesthe shock headless at the .entran e to thepumpmember blades.-The action of the turbine member is a vital factor incurtailing thef jsual extreme range of shockvelocity .at the purntpentrance.

The circumferential velocity of, the fluid entering the pump member issuccessively dominated: by the d turb .61" .rnember in the 1st an 2ndphases; :by th thir :s atp member in the '3rd'and 4th phases; and, bythe second turbine memberin the coupling phase. {Iheinflueneeof thethird turbine member permits apurnp'bladc entrance:

angle of appreciable negative character, which'is gessfigfih f" Thevariation in the fluid moment'of moment m Fr'omYstall this I to keep theshock head losses low in the 3rd, 4th and coupling phases.

The 4th phase begins when the second stator member free-whirls. Theshock head loss at the blade entrance of the second stator member isillustrated in Figure 13. The circumferential velocity of the fluidentering this member is dominated by the second turbine member for allphases of operation. The exit blade angle of the second turbine memberis a large angle of negative character. The second stator blades arecurved from a medium size entrance angle of negative character, to anexit angle which is approximately zero. The features of the secondstator member are blended in accordance with equation (g) of Figure 24,and as illustrated in Figure 13, the shock head is reduced to aninsignificant value in the coupling phase.

The coupling phase commences when the third stator member free-whirls.Figure 14 illstrates the shock head loss at the blade entrance of thisthird stator member. The circumferential velocity of the fluid enteringthis member is dominated, by the second stator member in the 1st, 2nd,and 3rd phases; and by the second turbine member in the 4th, and thecoupling phases. The third stator blades curve from a medium sizepositive angle at entrance to a large positive angle at exit.

In the coupling phase, the pump member and the first and second turbinemembers are the only members that appreciably influence the moment ofmomentum of the circulating fluid. Actually, the first and secondturbine members perform like a single turbine member, receiving fluidfrom the pump exit, and discharging it to the pump entrance.

This invention is not limited to the free-whirling sequence described,namely: the first stator member, the third turbine member, the secondstator member, and finally, the third stator member. By modifications ofblade angles, design radii and fluid path areas, the sequence may bechanged: the free-whirling of the third turbine member may start earlierthan that of the first stator member, or later than that of the secondstator member; also, the first and second stator members may becharacterized to independently free-whirl at, or about, the same time,and may for practical reasons he rotationally united.

In the embodiment of Figure 1, the first stator member, positioned inthe outer half of the fluid circuit, naturally develops high reactiontorque near stall. Thus, the desired torque ratio near stall is obtainedwith an unusually low rate of circulation; permitting the circulationpath area of the inner portion of the fluid circuit to be reduced about30 per cent from that in the outer portion. As shown in equation (k) ofFigure 26, this also reduces by about the same percentage, the rate ofcirculation required at the coupling point.

If this was a general change in circulation velocity through the fluidcircuit, the total circulation head loss would be reduced about 50 percent; however, the circulation velocity is only reduced in the outerportion, that of the inner portion being approximately unchanged; hence,the reduction in total circulation head loss is about 20 per cent.

Probably, the more important eflect is the increase in the gross head,which varies inversely as the rate of circulation, the increase in thegross head being about 40 per cent. Inasmuch as the gross head is thedenominator to which all the head losses are relative, a veryconsiderable gain in efliciency is obtained at the coupling point.

Otherwise, to acquire the desired efliciency, the coupling point (thespeed range of torque conversion) would be reduced; which would lowerthe speed and the developed power of the power source in the upperportion of the torque conversion range, likewise reducing the poweravailable at the output of the torque converter. For an automotiveapplication this is the upper portion of the passing zone in which, theability to pass quickly is frequently vital to safety; hence, thisunusual wide speed range of torque conversion for this embodiment isespecially desirable and important.

Other embodiments The one-way devices shown in the various embodimentsof this specification employ spring urged, wedging rollers. These areshown as one practical type of one-way devices. There are many othertypes of devices and mechanisms which may be used to render a torqueconverter member one-way acting. Just to emphasize the multiplicity anddiversity of such devices, without trying to be all-inclusive, some willbe mentioned.

In the class of one-way devices are arrangements employing: pawls,ratchets, wedging elements, toggles, sprags, or Wrapping elements.

Also, there are numerous types of clutches which may be actuated by aregulated power medium, such as: mechanical, hydraulic, vacuumatic,pneumatic, electrical, or magnetic. The influence of a clutch isequivalent to that of a one-way device: if the regulator is speed-ratioconscious; or if the regulator responds to torque reversal and torelative speed reversal between the clutch opposing elements,respectively, to release and to apply. For some situations, a speedresponsive regulator, with or without, supplementary influence of engineintake manifold pressure, and/or throttle position, may practicallysimulate the influence of a one-way device.

The improvements of this specification create a variety of torqueconverters having various combinations of bladed members, each of whichhas specific utility for particular applications. Some of thesecombinations are sonlaewhat diagrammatically illustrated in Figures17-21 11116 These illustrations also show some variations of attachingconstructions, and reaction and driven structures associating themembers with external components. No attempt is made to be all-inclusivein this respect. As a matter of simplicity, all of the embodiments areshown with coaxial input driving and output driven structures. Either orboth may be, parallel offset, angular offset or angular intersecting,drive structures. In general, these arrangements make the variousmembers more accessible, permitting many forms of attachingconstructions, and driving, driven, and reaction structures.Furthermore, a torque converter may be a built-in component of a drivecombination having a common enclosure.

In the description of these embodiments, the principal members arementioned, the distinctive features are explained, and the specificutility is disclosed. To avoid unnecessary repetition, a reasonabledegree of reliance is placed on the embodiment illustrated in Figure 1,which was described and explained in detail. Comparable members,elements and components are numbered with the same tenths and unitarydigits used in Figure l, but preluded with a particular hundredthsdigit. Members are considered comparable according to similarity ofinfluence and function, rather than similarity of names; e. g., if aparticular second stator member is most comparable to the third statormember of Figure 1, its reference numbers have the respective tenths andunitary digits of the third stator member in Figure 1. However, inFigure 21, there are members and attachments without counterparts inFigure lthese members and attachments have reference numbers 50l509incl.

Figure 17 somewhat diagrammatically illustrates an embodiment in which,one stator member 192 supplants the second and third stator members, 86and 92 respectively, of Figure 1. In sequence from the entrance of thepump member in the direction of fluid circulation, the members are: thepump member 150, the first turbine member 160, the first stator member180, the second turbine member 168, the second stator member 192, andthe third turbine member 174. A one-way device 121, extending from thefirst stator core 183 to the second stator core 195, prevents backwardrotation but permits forward rotation of the first stator member 180.

The operation of. this combination is similar to that of Figure 1,considered Without stator member 86. In consideration of this omission,a general revision of blade angles'with some modifications of radii isrequired to comply with the modified rate of circulation. Thiscombination is more simple and may be made axially shorter than that ofFigure 1. Characteristically, this combination gives a high stall torqueratio, but a rednced range of torque conversion, if high efiiciency atthe couplingpoint is considered a prime requisite. The utility of thiscombination tends to be for applications requiring a high stall torqueratio, and using a lower speed pewersource and consequently, a shcrterrange of torque conversion.

At present, there are automotive torque converters which have only onestator member, and that in the inner half of the fluid circuit. Relativeto those torque converters, the combination of Figure 17 is farsuperior, having higher efficiency, higher stall torque ratio, and mayhave'a wider range of torque conversion. The particular multi-staginghas very little adverse influence in the coupling phase, being inaccordance With the concepts of this specification; butcharacteristically, lowers the rate of circulation in the interest ofhigher eificiency. It pro- 7 vides the stall torque ratio with a lowerrate of circulation, and permits a reduced area of the inner portion ofthecirculation path, so that the rate of circulation is also lowered atand near the coupling point. Also, in accordance with thisspecification, the shock loss at the entrance of the inner stator membermay also be reduced and practically eliminated in the coupling base.Furthermore, the one-way acting third turbine member contributes to thesuperiority of this combination. It very effectively reduces shock headlosses at the pump entrance. Also, it provides the humpbacked form ofinput speed curve, permitting the engine more freedom to develop powerin the torque conversion range, thus increasing the available outputpower of the torque converter. 7

Figure 18 is a somewhat diagrammatic illustration of an embodimentdiffering from that of Figure l, in that, the third turbine member 74and its one-way device 20 is omitted. In sequence from the entrance ofthe .pump

member in the direction of fiuid circulation, the members are: the pumpmember 250, the first turbine member 260, the first stator member 280,the second turbine member 268, the secondstator member 286, and thethird stator member 292.

Relative to that of Figure 1, this combination is more simple and may bemade axially shorter. The operation is similar except for the influencesof the third turbine, which is omitted in this combination.Consequently, the

of course, tends to reduce somewhat, torque ratio near stall andefiiciency in the vicinity of the coupling point. The input speed curveextending from stall to the coupling has a distinct sagging tendency.Having the fluid discharged directly to the pump directly from the finalstator member, and having a pump exit blade angle of desirable negativedisposition, the input speed curve tends to be flat or to have a ratherflat slope from stall to the coupling point.v This is a characteristicwhich is more desirable usually for the heavy duty type than theautomotive type of engine; so, the utility of this arrangement tends toreside with heavy duty engines for which a relatively high stall speedis generally favorable. For this 'usage, this arrangement would provideunusually good of Figure 18. In sequence from the entranceof the pump"member in 'the direction of fluid circulation, the members shock lossat the pump entrance is considerably higher 7 near stall and in theregion of the coupling point. This,

are: the pump member 350, the first turbine member 360, the first statormember 380, the second turbine member 368 and the second stator member392. Abneway device 321, extending from the first stator core 3S3 to thesecond stator core 395, prevents backward rotation but permits forwardrotation of the first stator member 380; The major advantage of thisarrangement is simplicity. Regarding operation and characteristics, thiscombination is related to that of Figure 18, as the combination ofFigthe 17 is related to that of Figure 1.

These embodiments, illustrated in Figures 1, 17, 1-8 'andf19, arespecific torque converter combinations, in each of which, amulti-staging arrangement has unique features and characteristics asdisclosed and explained throughout this specification, providinghigh-torque ratio near stall, and generally improving efiiciency, butespecially so, in and near the coupling phase.

Figure 20 is an embodiment having the same combination of bladed membersas that of Figure 1, diagrammatically showing modifications of theattachmentconstruc tions of some of the members, respective utilitydepending on the nature of the application environment. Some of thesemodifications may be used, of course, for embodiments of Figures 1719,incl.

The members of this combination, in sequence from the entrance of thepump in the direction of circulation, are: the pump member 450, thefirstturbine member 460,

the first stator member 480, the second turbine member 468, the secondstator member 486, the third stator 'mem-' ber 492, and the thirdturbine member 47 4.

This illustration shows the one-way device of the third stator memberlocated at the outer end of the reaction shaft; bei g, a One-way device422 interposed between the stationary housing 410 and the reaction shaftelement 412. The ,third' stator member 492 is rotationally secured t'o'theinner end of the reaction shaft element; in

other words, extending from the third stator shell494, a: hub element496 is secured by key 497 to race 414 which is "splined to' reactionshaft element 412. This construction permits the use of a one-way devicewhich inherently has physical proportions inconsistent with the confinedspace inside the torque converter. Also, this reaction shaft elementrotates with the third stator member in the coupling phase; thus,reducing. the thrust sliding velocity between the thrust and theretaining surfaces, respectively, of the reaction structure and of thesecond turbine hub.

Theattaching construction for the first stator member 480 is a one-waydevice 421 extending from the first stator core 483 to the third statorcore 495, preventing backward but permitting forward rotation of thefirst stator member relative to its reaction structure, whichstructurally includes the third stator member.. This arrangement tendsto be advantageous for use with heavy dutyengines, having medium or lowoperating speeds. The principal.,advantage is a matter of balancingthrust forces of the first and the third stator membersnear stall, thefirst and the second stator members exert large thrustforces, axiallytowards the en gine,.but that of the third stator member is in oppositedirection. Also,

for use with a lower speed power source, this speel differential wouldbe reduced accordingly, retaining reasonable sliding velocities betweenthe elements of oneway device421. i

It may 'be noted that the second stator member 436 has "a single one-waydevice 423 in this arrangement, in.

21 consideration of being relieved of the first stator reaction torque.

As shown, circumferentially spaced screws 465 provide the driveconnection between mating parts 464 and 473, respectively, of the firstturbine member 460 and the second turbine member 468. This departurefrom the square-head pins, shown in the preceding embodiments, islargely a matter of preference.

The other structural departure of Figure 20 from Figure 1, is theattaching construction for the third turbine member, which is arotationally rigid structure uniting the third and the first turbinemembers. Specifically, the attaching construction comprises a rigidconjunctive structure 42!) extending from the third turbine core 477 tothe first turbine core 463. As shown for exemplification, it is anannular web cast integrally with the third turbine member 474 and thefirst turbine member 460. Relative to the embodiments of Figures 1 and17, the principal advantage of this construction is simplicity, that is,the elimination of a one-way device. Otherwise, this arrangement is lessdesirable. It tends to have higher shock head losses at the entrances ofthe third turbine member and the pump member. Also, it does not providethe desirable humpbacked input speed curve; in contrast, the input speedcurve has a slight sagging tendency between stall and the couplingpoint. However, the arrangement is more favorable for automotiveapplications than arrangements having the fluid discharged directly tothe pump entrance from the final stator exit; this interposed turbinemember has a rising trend influence on the input speed curve, permittingthe pump blades at exit to have a desirable negative angle.

In the discussions of the preceding embodiments, three types of inputspeed curves were mentioned. These deserve further comment relative tospecific fundamental influences. In a torque converter, the rate ofcirculation naturally has a general decreasing trend from stall to thecoupling point.' Similarly, this factor would provide a rising pumpspeed inversely proportional to the rate of circulation. However, it isdesirable to have the pump blades at exit disposed at a medium size,negative angle, to avoid an extreme angle of the blades at the entranceof the first turbine member, and to reduce near stall, the conversion ofkinetic to pressure energy in the first turbine member. Singularly, anegative disposition of the pump blades at exit, increases the pumpspeed to offset the circumferential component of the blades.Consequently, for the varying rate of circulation, the influence atstall is greater than at the coupling point; thus, re ducing the generalrising slope of the input speed curve. Another factor which has animportant influence on the input speed curve is the nature of variationof the moment of momentum of the fluid approaching the pump member.

For an arrangement having the final stator member discharging directlyto the pump entrance, the moment of momentum of the fluid entering thepump, as a vector quantity, varies from large at stall to small at thecoupling point, being proportional to the second power of the rate ofcirculation. Singularly, this factor influences the input speed curve inthe same manner as a backward disposition of the blades at the exit ofthe pump member. Consequently, for arrangements as shown in Figures 18and 19, the general slope of the input speed curve naturally is somewhatflat, with a sagging tendency between stall and the coupling point; infact, the stall speed may actually be higher than the coupling pointspeed. A rather flat input speed curve is desirable for many heavy dutyengine applications. For the many automotive torque converters havingdirect discharge from the final stator member to the pump member ormembers, the desirable negative disposition of the blades at the exit ofthe principal pump is sacrificed, at least to a large degree, to obtainan acceptable rising trend of the input speed curve.

A turbine member, interposed between the final stator and the pumpmember, and in fixed association with the output power structure,discharges fluid to the pump entrance with a moment of momentum whichvectorially increases from stall to the coupling point. Thisarrangement, shown in Figure 20, provides a rising input speed curve ofa pump member having blades with a desirable negative disposition atexit.

A one-way acting turbine member interposed between the final statormember and the pump entrance, as shown in Figures 1 and 17, is thearrangement most desirable for automotive torque converters. It permitsa desirable negative disposition of the pump blades at exit, and itprovides the humpbacked input speed curve, allowing the engine unusualfreedom in the torque conversion range to develop power.

Figure 21 illustrates one embodiment with extensive multi-staging. Insequence from the entrance of the pump member in the normal direction offluid circulation, the members are: the pump member 550, the firstturbine member 560, the first stator member 580, the second turbinemember 501, the second stator member 506, the third turbine member 568,the third stator member 508, the fourth turbine member 503, the fourthstator member 586, and the fifth stator member 592.

Each stator member may have a respective one-way device to render itone-way acting, but for practical simplification, members whichnaturally have similar forward speed characteristics-or may have, withslight changes of blade dispositionare joined together and served with asingle one-way device. The fifth stator member 592 has an attachingconstruction comprising, an attaching flange 596 secured to a one-waydevice, 522 including a race 514, splined to reaction shaft element 512which is secured to the stationary housing 510. The fourth stator memberhas an attaching construction comprising, an attaching element securedto two one-way devices, the common race 514 of which is splined toreaction shaft 512. The two one-way devices are used to provide adequatecapacity for the reaction torques of preceding stator members which actthrough this structure. The third stator member 508 is a precedingstator member in the fluid circuit relative to the fourth stator member586, being in this case, the nearest preceding stator. It has similarforward speed characteristics and is joined to the fourth stator byelement 509.

The second stator member 506 is a subsequent stator relative to thefirst stator member 530. These particular members tend to have similarforward speed characteristics and are joined together by respectiveattaching elements 507 and 585. The common attaching constructionextends to the fourth stator core 589 and includes one-way device 521.

The turbine members drive through the third turbine member 568 which hasan attaching element 572 secured to the driven hub structure 531, keyed(preferably splined) to the output shaft 530. The fourth turbine member563 is secured by an attaching flange 504 to a mating element 505associated with the core of the third turbine member. The second turbinemember 501 and the first turbine member 560 are secured to a flangeelement 573 extending outwardly from the third turbine member; thesecond, by attaching element 502 and the first turbine, by attachingelement 564.

The pump driving structure is quite similar to that described for Figure1.

Obviously, there are many structural variations which could be employed.Also, the arrangement could be varied. Two successive stator members,instead of one, could be interposed between turbine members, or thefourth and the fifth stator members could be replaced with a singlemember. Furthermore, a one-way acting turbine member could be interposedbetween the final stator member and the pump member, as in Figure 1, toprovide a humpbacked input speed curve.

As shown, the embodiment of Figure 21 has four phases of operation. Fromstall through the first phase, it is a four-stage torque converterhaving five stator members contributing reaction torque. The secondphase starts when the first and second stator members freewhirl inunisonance. In this phase it is a two-stage torque converter havingthree active stator members. The third phase begins when the third andthe fourth stator members free-whirl together. The third phase is asinglestage operation with only the fifth stator member active. Thefourth phase, which is the coupling operation, commences when the fifthstator member free-whirls. Of course, with a respective one-way devicefor each stator member, there could be more phases with each step havinga milder influence. V a

This embodiment has a stator arrangement with three levels of mechanicaladvantage in the torque conversion range, generally in accord with thereaction torque requirements, thus providing the required reactiontorques with relative low rates of circulation. Unless, an extremelyhigh stall torque ratio is required, the circulation path areas at theexits of the fifth stator and the fourth turbine members, may be maderelatively small 1 to reduce the rate of circulation and to aidefficiency near and in the coupling phase, as shown in equation (k) ofFigure 26. Most of the shock head losses may be practically eliminatedin a large portion of'the coupling phase by characterizing most of thestator and turbine members with features, respectively in accordancewith equation (g) of Figure 24, and equation (,0 of Figure 25.

Hence, the improvements disclosed in this specification, not onlyprovide superior torque converters for light duty usage, such asautomotive; but furnishestorque converters for heavy duty applicationswhich are uniquely characterized for high stall torque ratio, and higheffi- 1 ciency in general, but especially in the 'couplingphase ofoperation. Digest 7 The principal invention of this specification is theconcept of fundamental improvements in the performance of variouscombinations of bladed members constituting hydrodynamictorqueconverters in general; the performance factors being torque ratio andefficiency in the torque conversion range, and eflicienc'y in thecoupling phase of operation.

The conceptive ideas relate, not only to the curtainment of shock headand circulation head losses, but to the attainment of the desired torquemultiplication and the power transmission characteristics with unusuallylow rates of circulation, at least in some phases, but preferably in allphases. A reduction in the rate of circulation reduces the attendingcirculation head loss and some of the shock head losses. A low rate ofcirculation is particularly important to minimize the relative influenceof the simultaneous circulation and shock head lossesthe denominator, towhich the head losses are relative is the gross head, which variesinversely as the rate of circulation, and consequently is higher for alow rate of circulation.

The physical modes of attainment include multi-staging, preferablyhaving a plural stator construction with at least one stator memberpositioned in the outer half of the fluid circuit, and at least onestator member positioned in the inner half. It also includes having eachThis specification compri'ses several'distinct ihventious which areclosely related, having utility in combination,

being in the same classification, in the same status of the art, andinvolving the same field of search.- The concepts and modes ofattainment of these inve'ntionsmay' be stated briefly as follows:

Having a free-whirling stator member characterized with physicalfeatures so that, under the influence of the circulating fluid, thecircumferential 'velocities of the fluid before and after entrance aresynchronized in the coupling phase. The mode of attainment beingphysical features specified in equation (g) of Figure 24. 'Thisimprovement isvery desirable for outer stator members which free-whirlin several late phases.

For two turbine members interrupted by a free-whirling stator member,having the neighboring features of the turbine members physicallycharacterized, so that in conformity with vortex flow, thecircumferential velocities before and after entrance to the followingturbine member are synchronized in the coupling phase, the mode ofattainment being physical features specified in equation (j) of Figure25.

Acquiring the desired range of torque conversion with an unusually low'rate of circulation is physically achieved by using a circulation patharea at the exit of the final stator member and/ or the exit of thenearest preceding turbine member, smaller than that in the outer half ofthe fluid circuit, specifically at the exit of the first outer statormember. ,The influence of the circulation path area on the rate ofcirculation at the coupling point is shown by equation (k) of Figure 26.The mode of physical attainment also includes'an outer stator memherwhich, not only permits the particular areas reduction, but helps toprovide required reaction torque at stall with an unusually low rate ofcirculation. generally reduced rate of circulation helps efficiency andgrants the pump and turbine members larger radial prostator memberpractically one-way acting, firm .back- 7 wardly but yieldableforwardly. Each of these features,

as Well as the combination of the particular features, is

portions which obviously are desirable in the coupling phase.

Also, the. inventive concept of a heavy duty type of torque converterhaving a high stall torque ratio and a 7 very efiicient coupling phaseof operation. Hitherto, these characteristics have not been attained andgenerally have been considered too conflicting to permit achievement.

The mode of attainment is a torque converter having ex tensivemulti-staging and characterized with at least some of the precedingimprovements in combination.

So far as I am aware I am the first to have the conception of, or toprovide in a hydrodynamic torque converter, either one, or anycombination, of the preceding inventions. Hence, I claim theseinventions generically in' torque converter combinations,individuallyand in com-1 bination with each other. And, I. claim these inventionsgenerically in appropriate subcombinations of torque con- .verters.

Also, I claim plural species with each of these inventions individually,and in combination with each other, and with supplementary claimsfurther defining form, structure and/or features.

As has been thoroughly emphasized, the inventions hereof pertain toimprovements in hydrodynamic trans mission of power, during which, therate of fluid circula tion of a combination of members varies with thephase of operation and the power transmitted, but is maintained in thesame general direction with respect to'the procession of members in thetoroidal circuit; and that direction is referred to as the direction offluid circulation, or according to SAE recommendations, the fluid flowdirec: tion.

Also, in' accordance with the aforestated SAE recommendations, theterms, first, second, third, and final, are used in the foregoingdescriptions and in the appended claims to indicate the sequence'oftheparticular character ofmctnbor in thefluid flow direction'in' This i25 the recirculating path, referred to as the circuit, starting at theentrance of the first pump member.

Accordingly, a preceding member relative to a specified member means amember which is situated in the fluid circuit ahead of that specifiedmember, that is, is situated from the specified member in the directioncounter to the fluid flow direction; and a subsequent or followingmember relative to a specified member means a member which is situatedin the fluid circuit from the specified member in the same direction asthat of the fluid flow.

Similarly, for two successive members of like character, such as twosuccessive turbines interrupted by an interposed stator, the twosuccessive turbines are separately referred to as the preceding turbineand the following turbine, based on the reciprocal relationship in thecircuit of one to the other.

The terms, juxtaposed, interposed, and adjacent, are used in the claimsin reference to the positioning of bladed-members to indicate sequentialposition in the procession of bladed-members in the toroidal fluidcircuit, rather than the extent of the unoccupied intervening space inthe fluid circuit.

In this specification, the usage of the terms member and members isconfined to references to the bladedmembers. To eliminate unessentialwords in the claims, the word member is usually omitted where a specificcharacter of member is recited. Accordingly, as used in the claims: pumpmeans a pump member; turbine, a turbine member; and stator, a statormember.

In conformity with general practice, the phases of operation in theforegoing disclosures are numbered sequentially from stall to thecoupling point, the operation thereafter being the coupling phase.Accordingly, in reference to a portion of the torque conversion range ofoperation, an early phase means a phase of operation in the first halfof that torque conversion range which starts at stall; and, a late phaseof torque conversion means a phase of operation in the second half ofthat torque conversion range which terminates at the coupling point.

It is, of course, understood that'the present invention is not limitedto the particular forms and structures shown in the drawings, orotherwise revealed, for disclosure and explanatory purposes, but alsoembraces modifications within the scope of the appended claims.

I claim:

1. In a hydrodynamic torque converter drive having pump, stator, andturbine bladed-members arranged in spaced relationship in a toroidalcircuit for fluid recirculation, the combination comprising: a pumpsituated with its entrance in the inner half and its exit in the outerhalf of said circuit, and means to connect said pump to an input powerstructure; a plurality of stators including a first stator situated inthe outer half of said circuit and a final stator situated in the innerhalf of said circuit; reaction structure means to associate saidplurality of stators with a stationary support structure to therewithrender each stator thereof firm against backward rotation, said reactionstructure means including one-way device means arranged to permitforward rotation operative to render each one of said plurality ofstators ineffective to vectorially reduce the moment of momentum ofcirculating fluid, said first stator being thereby and whereforeforwardly rotatable relative to said final stator; a plurality ofturbines including and arranged with a first turbine juxtaposed to saidpump exit and a final turbine situated with its exit in the inner halfof said circuit, and having two successive turbines thereof separatedfrom each other by at least one of said stators; driven structure meansto associate said turbines with an output power shaft to therewithafford, for each of said turbines, restraint of forward rotation for theconversion and transmission of energy to said output shaft; and,entrance and exit features of at least one of said stators correlated 26and related to the environment as set forth in the ensuing equation,wherein the respective environment for each so particularized stator ispartially expressed by features of the nearest preceding one of saidturbines R 2 fii f. en l -(f3) in which Rptx, Rsn and Rsx are the designradii, ft., Aptx, Ash and Asx are the circulation path areas, sq. ft.,Bptx, Bsn and Bsx are the blade angles, respectively in each grouping,of said preceding turbine exit, of the particular stator entrance, andof the particular stator exit, and, for wide-open throttle input poweroperation, Nt is for said preceding turbine a rotational speed, R. P.S., which is 10 to 20 per cent faster than the coupling point speedthereof, and Q is the rate of fluid circulation, cu. ft. per sec.,concurrent with Na.

2. The combination defined in claim 1 in which: said plurality ofstators includes two unisonant stators which independently tend torotate forwardly almost simultaneously and approximately in unisonance,one of said unisonant stators being in the inner half of said circuit,and relative to that one, the other being a preceding stator by itsposition in said circuit; and, said reaction structure means includesmeans to rotationally secure said unisonant stators together, and areaction shaft and a one-way device arranged to connect said unisonantstators with said stationary support structure and to therewith preventbackward rotation and permit forward rotation of said unisonant stators.

3. The combination defined in claim 1 in which: said plurality ofstators includes two unisonant stators which independently tend torotate forwardly almost simultaneously and approximately in unisonance,one of said unisonant stators being in the outer half of said circuit,and relative to that one, the other being a subsequent stator by itsposition in said circuit, and a stator situated in the inner half ofsaid circuit; and, said reaction structure means includes means torotationally secure said unisonant stators together, and a core situatedone-Way device adapted to prevent backward rotation and to permitforward rotation of said unisonant stators relative to said statorsituated in the inner half of said circuit.

4. The combination defined in claim 1 and including the relationship ofcirculation path areas in which the average of the exit circulation patharea of said final stator and that of the nearest one of said turbinespreceding said final stator is 0.60 to 0.90 of the exit circulation patharea of said first stator.

5. The combination defined in claim 1 and including particular featuresof said two successive turbines, said two successive turbines being apreceding turbine and a following turbine by disposition relative toeach other, being rotationally united by said driven structure means,and having exit features of said preceding turbine and entrance featuresof said following turbine correlated and related to the environment asset forth in the ensuing equation tan B in which, Rptx and Rftn are thedesign radii, ft., Aptx and Arm are the circulation path areas, sq. ft.,and Bptx and Brm are the blade angles, respectively in each grouping, ofsaid preceding turbine exit, and of said following turbine entrance,and, for wide-open throttle input power operation, Nb is for saidsuccessive turbines a rotational speed, R. P. S., which is 10 to 20 percent faster than the coupling point speed thereof, and Q is 'the rate offluid circulation, cu. ft. per sec., concurrent with Nt'. V

i a 6. The combination defined in claim and including the relationshipof circulation path areas in which the average of the exit circulationpath area of said final stator and that of the nearest one of saidturbines preceding said final stator is 0.60 to 0900i the exitcirculation path area of said first stator.

, 7. In a hydrodynamic torque converter drive having pump, stator, andturbine bladed-members arranged in spaced relationship in a toroidalcircuit for fluid recirculation, the combination comprisingffapumpsituated with its entrance in the inner half and its exit in the outerhaIf of said circuit, and means to connect said pump to an input powerstructure; a plurality of stators including a first stator situated inthe outer half of said circuit and a final stator situated in the innerhalf of said circuit; reaction structure means to associate saidplurality of stators with a sationary support structure to therewithrender eachrstator thereof firm againstbackward rotation, said reactionstructure means including one-way device means arranged to permitforward rotation operative to render each one of said plurality ofstators ineffective to vectorially reduce the moment of momentum ofcirculating fluid, said first stator being thereby and whereforeforwardly rotatable relativ e'to said final stator; a plurality ofturbines including and arranged with a first turbine juxtaposed to saidpump exit and a final turbine situated with its exitin the inner half ofsaid circuit, and having two successive turbines thereof separated fromeach other by at least one of said'stators; driven structure means toassociate said turbines with an output power shaft totherewith afford,for each of said turbines, restraint of forward rotation for theconversion and transmission-ofe nergy to said output shaft; and,particular features of said twosuccessive turbines, said two successiveturbines being a preceding and a following turbine by dispositionrelative to each other, being rotationally unitedfby said drivenstructure means, and having exit features or said preceding turbine andentrance features of said following turbine correlated and related tothe environment asset forth in the ensuing equationin which, R m andRftn are the design radii, ft., 'Aptx and Ana are the circulation pathareas, sq; ft., and Bptx and Bria are the blade angles, respectivelyin'each grouping, of said preceding turbine exit, and of said followingturbine entrance, and, for wide-open throttle input power operation, NCis for said successive turbines a rotational speed, R'. 'P. 8:, which is10 to 20 per cent faster than the coupling point speed thereof, and Q isthe rate of fluid circulation, cu. ft. per sec., concurrent with Nt'.

8. The combination defined in claim 7 and including the relationship ofcirculation path areas in which the average of the exit circulation patharea of said final,

stator and that of the nearest one of said turbines preceding said finalstator is 0.60 to 0.90 of the exitcirculation path area of said firststator. 7

9. In a hydrodynamic torque converter drive having pump, stator, andturbine bladed-members arranged in V spaced relationship in a toroidalcircuit for fluid recirculation, the combination comprising: a pumpsituated with its'entran'ce in the inner half and its exit inthe outerhalf of said circuit, and means to connect said pump to an input powerstructure; "a plurality of stators including a first stator situated inthe outer half of said circuit and afinal stator situated in the. innerhalf of said circuit; reaction structure means to associate saidplurality 'of statorswith a stationary support structure to therewithrender each stator thereof firm against backward rotaas tion,saidr'eaction structure means including one w'ay device means arrangedto permit forward'rotation operative to render each one of saidpluralityof stators'in efiective to vectorially reduce the moment of momentum ofcirculating fluid, said first stator being thereby and whereforeforwardly rotatable relative to said final stator;

a plurality of turbines including and arranged with a first turbinejuxtaposed to said pump exit and a final turbine situated with its exitin the inner half of said circuit, and having 'two successive turbinesthereof separated rom each other by at least one of said' statorsfdrivenstructure means to associate said turbines with an output.

pump, stator, and turbine bladed-members arranged in.

spaced relationship in a toroidal circuit for fluid recirculation, thecombination comprising: an outer stator situated in the outer half ofsaid circuit and near to the exit ther'eat of a preceding turbine; aninner stator situated in the inner half of said circuit and near to theexit.

thereat of a preceding turbine; reaction structure means to associatesaid inner and outer stators with a stationary support structure totherewith render each of said stators firm against backward rotation,said reaction structure means including one-way devicermeans to permitforward rotation of said inner and outer stators and to permitforwardtrotation of said outer stator relative to said inner stator;and, entrance and exit features of at least one of said inner and outerstators correlated and related to the environment as set forth in theensuing equation, wherein the respective environment for each soparticulari'zed stator is partially expressed by'features of the nearestpreceding turbine v a R; i 111s, Tith efs *f hil injwhi ch, Rptx -Rsnand Rsx are the design radii, ft., Aptx, Asn andAsx are the circulationpath areas, sq. ft., B tx, B and Bsx are the blade angles, respectivelyin each grouping, of said precedingturbine exit, of the particularstator entrance, and of the particular stator. exit, and, for wide-openthrottle input power operation, Nt' is for said preceding turbine arotational speed, R. P. S., which is 10 to 20 per cent faster than thecoupling point speed thereof, and Qi is the rate of fluid circulation,cu. ft. per sec., concurrent with Nt'. V I V I V 11 The combinationdefined in claim 10 in which, based on the direction of 'fluid flow,said outer stator is the first stator and said inner stator'is the finalstator in the energy extraction portion of saidcircuit; and said statorfentures include the relationship the exit circu-. lation path area ofsaid inner stator being 0.60 to 0.90

circulation, the combination comprising: two successive,

turbines situated in said circuit withan intervening space adaptable forat least one' forwardly rotatable stator, said successive turbinesbeinga preceding turbine and a following turbine by disposition relativeto each other;

driven structure means to associate said successive JturblliES Wlth anoutput power shaft to therewith afford'restraintof forward rotation-forthe conversion and trans-- mission of energy to said output shaft, saiddriven structure means including means to rotationally unite saidsuccessive turbines; and, em; features of said preceding turbine andentrance features of said following turbine correlated and related tothe environment as set forth in the ensuing equation in which, Rptx andRim are the design radii, ft., Aptx and Arm are the circulation pathareas, sq. ft., and Bptx and Brm are the blade angles, respectively ineach grouping, of said preceding turbine exit, and of said followingturbine entrance, and, for wide-open throttle input power operation, Nt.is for said successive turbines a rotational speed, R. P. S., which isto 20 per cent faster than the coupling point speed thereof, and Q isthe rate of fluid circulation, cu. ft. per sec., concurrent with Na.

13. In a hydrodynamic torque converter drive having pump, stator, andturbine bladed-members arranged in spaced relationship in a toroidalcircuit for fluid recirculation, the combination comprising: an outerstator situated in the outer half of said circuit, and an inner statorsituated in the inner half of said circuit, said outer stator being thefirst stator and said inner stator being the final stator in the energyextraction portion of said circuit, in accordance with the direction offluid flow; reaction structure means to associate said inner and outerstators with a stationary support structure to therewith render each ofsaid stators firm against backward rotation, said reaction structuremeans including one-way device means to permit forward rotation of saidinner and outer stators including forward rotation of said outer statorrelative to said inner stator; and, the relationship of the exitcirculation path area of said inner stator being 0.60 to 0.90 of theexit circulation path area of said outer stator.

14. In a hydrodynamic torque converter drive having bladed-members, onepump, three stators, and three turbines, arranged in spaced relationshipin a toroidal circuit for fluid recirculation, the combinationcomprising: a pump situated with its entrance in the inner half and itsexit in the outer half of said circuit, and means to connect said pumpto an input power structure; a first stator situated in the outer halfof said circuit with an interrupted space between its entrance and saidpump exit; a second stator situated in the inner half of said circuitwith two interrupted spaces between its exit and said pump entrance; athird SEItOr situated in the inner half of said circuit with itsentrance adjacent to said second stator exit; reaction structure meansto associate said stators with a stationary support structure totherewith render each of said stators firm against backward rotation,said reaction structure means including one-way device means arranged topermit forward rotation operative to render each one of said statorsineffective to vectorially reduce the moment of momentum of circulatingfluid, said first stator being thereby and wherefore forwardly rotatablerelative to said third stator; a first turbine interposed between saidpump exit and said first stator entrance; a second turbine situated withits entrance adjacent to the exit of said first stator and its exitadjacent to the entrance of said second stator; a third turbineinterposed between the exit of said third stator and said pump entrance;driven structure means to associate said turbines with an output powershaft to therewith afford, for each of said turbines, restraint offorward rotation for the conversion and transmission of energy to saidoutput shaft; and, entrance and exit features of at least one of saidstators correlated and related to the environment as set forth in theensuing equation, wherein the respective environment for each soparticularize'd stator is partially 30 expressed by features of thenearest'preceding one of said turbines R 2 I 871. 2 Ti. T? Eda) inwhich, Rptx, R511 and REX are the design radii, ft., Aptx, A511 and Asxare the circulation path areas, sq. ft., Bptx, B511 and Bsx are theblade angles, respectively in each grouping, of said preceding turbineexit, of the particular stator entrance, and of the particular statorexit, and, for wide-open throttle input power operation, Nt' is for saidpreceding turbine a rotational speed, R. P. S., which is 10 to 20 percent faster than the coupling point speed thereof, and Q is the rate offluid circulation, cu. ft. per sec., concurrent with Nt'.

15. The combination defined in claim 14 in which said reaction structuremeans includes: a reaction shaft and a one-way device arranged toconnect said third stator with said stationary support structure and totherewith prevent backward rotation and permit forward rotation of saidthird stator; a one-way device adapted to prevent backward rotation andto permit forward rotation of said second stator relative to saidreaction shaft; and, a core situated one-way device operative for saidfirst stator to prevent backward rotation relative to one, and to permitforward rotation relative to both, of said second and said thirdstators.

16. The combination defined in claim 14 in which said driven structuremeans includes a driven element extending from a core element of saidthird turbine to a core element of said first turbine, said drivenelement including a one-way device interposed therein and operativetherewith to permit backward rotation and to prevent forward rotation ofsaid third turbine relative to said first turbine.

17. The combination defined in claim 14 and including the relationshipof circulation path areas in which the average of the exit circulationpath area of said third stator and that of said second turbine is 0.60to 0.90 of the exit circulation path area of said first stator.

18. The combination defined in claim 14 in which said driven structuremeans include means to rotationally unite said first and said secondturbines; and, in which the exit features'of said first turbine and theentrance features of said second turbine are correlated and related tothe environment as set forth in the ensuing equation, wherein, bydisposition relative to each other, said first turbine is the precedingturbine, said second turbine is the following turbine, and together aresuccessive turbines in which, Rptx and Rftn are the design radii, ft.,Aptx and Arm are the circulation path areas, sq. ft., and Bptx and Bftnare the blade angles, respectively in each grouping, of said precedingturbine exit, and of said following turbine entrance, and, for wide-openthrottle input power operation, Nt is for said successive turbines arotational speed, R. P. S., which is 10 to 20 per cent faster than thecoupling point speed thereof, and Q is the rate of fluid circulation,cu. ft. per sec., concurrent with Nt'.

19. The combination defined in claim 18 and including the relationshipof circulation path areas in which the average of the exit circulationpath area of said third stator and that of said second turbine is 0.60to 0.90 of the exit circulation path area of said first stator.

20. In a hydrodynamic torque converter drive having bladed-members, onepump, three stators, and three turbines, arranged in spaced relationshipin a toroidal circuit for fluid recirculation, the combinationcomprising: a pump situated with its entrance in the inner half and its

